Featured Research

from universities, journals, and other organizations

Earth's Magnetic Field Could Help Protect Astronauts Working On The Moon

Date:

December 13, 2007

Source:

University of Washington

Summary:

It has been 35 years since humans last walked on the moon, but there has been much recent discussion about returning, either for exploration or to stage a mission to Mars. However, there are concerns about potential radiation danger for astronauts during long missions on the lunar surface. New research indicates that Earth's magnetic field can provide some protection from radiation for humans on the moon, new research shows.

Share This

It has been 35 years since humans last walked on the moon, but there has been much recent discussion about returning, either for exploration or to stage a mission to Mars. However, there are concerns about potential radiation danger for astronauts during long missions on the lunar surface.

Related Articles

A significant part of that danger results from solar storms, which can shoot particles from the sun to Earth at nearly the speed of light and can heat oxygen in the Earth's ionosphere and send it in a hazardous stream toward the moon.

Earth is largely protected by its magnetic field, or magnetosphere, but new University of Washington research shows that some parts of the moon also are protected by the magnetosphere for seven days during the 28-day orbit around Earth.

"We found that there were areas of the moon that would be completely protected by the magnetosphere and other areas that are not protected at all," said Erika Harnett, a UW assistant research professor of Earth and space sciences.

Solar energetic particles, which are generated during solar storms, carry enough energy to disrupt communications on Earth or even kill satellites in Earth orbit. During those same storms, particles from Earth's ionosphere, primarily oxygen, also can become significantly energized. Though they are not as powerful as solar energetic particles, they still pose a significant threat to astronauts working on the moon, or even en route to Mars.

Using computers to model properties of the magnetosphere, Harnett found that while solar storms can increase the danger from ionosphere particles hitting the moon they also trigger conditions in the magnetosphere that deflect many hazardous solar particles.

Particles with high enough energy can pass directly through a human without much damage, Harnett said, but particles packing slightly less oomph, though unfelt by a human, can lodge in a person. Typically it's not just one particle but many, and the accompanying radiation can damage cells, she said.

Some of the research is detailed in a poster being presented at the American Geophysical Union annual meeting in San Francisco, while other aspects are in a paper published last month in the online edition of Geophysical Research Letters. Robert Winglee, a UW Earth and space sciences professor, is co-author of the work, which was funded by the National Science Foundation and NASA.

In the longest missions of NASA's Apollo Program, astronauts spent just a few days on the moon. The last mission, Apollo 17, was launched Dec. 7, 1972, landed on the moon on Dec. 11 and arrived back on Earth on Dec. 19.

"During Apollo, people were not on the moon for very long so there wasn't the concern about the radiation hazard to humans as there is with longer missions," Harnett said.

Today there is much greater understanding of the danger posed by solar energetic particles, particularly because of the adverse effects they can have on satellite communications during periods of intense solar flare activity.

"The problem is that we can't predict when this activity is going to take place so we can't warn astronauts to take shelter, so they could be vulnerable when the moon is outside the magnetosphere," Harnett said. "The particles travel near the speed of light, so when we see them generated on the sun's surface they will arrive in a few minutes and there is little time to react."

The new research could help determine when it is safe for astronauts to work far from a lunar base, she said. But she added that models used in the work suggest that energetic oxygen from Earth's ionosphere also poses a danger, even though it is less energetic than solar particles.

"It wouldn't kill someone instantly, but it definitely could increase the radiation exposure for an astronaut on the moon," Harnett said.

However, she noted that the danger from energetic oxygen could be overstated because the models do not take into account the positive electrical charge on the daylight side of the moon that likely would significantly slow the oxygen stream.

University of Washington. "Earth's Magnetic Field Could Help Protect Astronauts Working On The Moon." ScienceDaily. ScienceDaily, 13 December 2007. <www.sciencedaily.com/releases/2007/12/071211094857.htm>.

University of Washington. (2007, December 13). Earth's Magnetic Field Could Help Protect Astronauts Working On The Moon. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2007/12/071211094857.htm

University of Washington. "Earth's Magnetic Field Could Help Protect Astronauts Working On The Moon." ScienceDaily. www.sciencedaily.com/releases/2007/12/071211094857.htm (accessed March 3, 2015).

More From ScienceDaily

More Space & Time News

Featured Research

Mar. 3, 2015 — Meteorologists sometimes struggle to accurately predict the weather here on Earth, but now we can find out how cloudy it is on planets outside our solar system, thanks to new ... full story

Mar. 3, 2015 — Recent research contributes to the effort to determine the nature of dark matter, one of the most important mysteries in physics. As indirect evidence provided by its gravitational effects, dark ... full story

Mar. 2, 2015 — Dust plays an extremely important role in the universe -- both in the formation of planets and new stars. But the earliest galaxies had no dust, only gas. Now an international team of astronomers has ... full story

Mar. 2, 2015 — NASA's Dawn spacecraft has returned new images captured on approach to its historic orbit insertion at the dwarf planet Ceres. Dawn will be the first mission to successfully visit a dwarf planet when ... full story

Mar. 2, 2015 — An international team of researchers has demonstrated a way to assess the quality of water on Earth from space by using satellite technology that can visualize pollution levels otherwise invisible to ... full story

Feb. 27, 2015 — A new type of methane-based, oxygen-free life form that can metabolize and reproduce similar to life on Earth has been modeled. It is theorized to have a cell membrane, composed of small organic ... full story

Feb. 27, 2015 — Astronomers using data from NASA's Wide-field Infrared Survey Explorer, or WISE, have found a cluster of stars forming at the very edge of our Milky Way galaxy. This is the first time astronomers ... full story

Feb. 26, 2015 — If you put a camera in the ice machine and watched water turn into ice, the process would look simple. But the mechanism behind liquids turning to solids is actually quite complex, and understanding ... full story

Feb. 26, 2015 — Like a cowboy at a rodeo, NASA's newest Earth-observing satellite, the Soil Moisture Active Passive (SMAP), has triumphantly raised its "arm" and unfurled a huge golden "lasso" (antenna) that it will ... full story

NASA EDGE: SMAP Launch

NASA (Mar. 2, 2015) — Join NASA EDGE as they cover the launch of the Soil Moisture Active Passive (SMAP) spacecraft live from Vandenberg Air Force Base. Special guests include NASA Administrator Charlie Bolden, SMAP Project System Engineer Shawn Goodman and Lt Col Brande Walton and Joseph Sims from the Air Force. No word on the Co-Host&apos;s whereabouts.
Video provided by NASA

Related Stories

May 28, 2014 — A recent review of hundreds of chemical analyses of Moon rocks indicates that the amount of water in the Moon's interior varies regionally -- revealing clues about how water originated and was ... full story

Apr. 23, 2014 — Rats exposed to high-energy particles, simulating conditions astronauts would face on a long-term deep space mission, show lapses in attention and slower reaction times, even when the radiation ... full story

Nov. 8, 2012 — The complexities of traveling to and working in space present challenges to astronauts that NASA scientists and engineers have been working on since Neil Armstrong and Buzz Aldrin first stepped on ... full story

Sep. 18, 2012 — For six weeks NASA's Mars rover Curiosity has been working on the Red Planet. NASA also plans to send humans to Mars within the next 20 years. On the flight and during the stay on Moon or Mars, ... full story

Nov. 9, 2011 — The presence of magnetized rocks on the surface of the moon, which has no global magnetic field, has been a mystery since the days of the Apollo program. Now a team of scientists has proposed a novel ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.